march 2009 rev 1 1/10 AN2933 application note demo board user guidelines fo r the ts4999 filter-free stereo 2 x 2.8 w class d audio power amplifier with selectable 3d effect introduction this application note concerns the ts4999 demonstration board, designed to evaluate the stereo class d audio differential amplifier ts4999. this document provides: a brief description of the ts4999 device. a description of the demonstration board and all of its components. the layout of the demonstration board. about the ts4999 the ts4999 is a fully-differential class d stereo power amplifier. it can drive up to 1.35 w into an 8 load at 5 v per channel. the device has four different gain settings utilizing two discrete pins, g0 and g1. pop and click reduction circuitry provides low on/o ff switch noise while a llowing the device to start within 8 ms. 3d enhancement effects are selected through one digital input pin that allows more amazing stereo audio sound. two standby pins (active low) allow each channel to be switched off separately. the ts4999 is available in an 18-bump flip-chip package. key features of the ts4999 operating range from v cc = 2.4 v to 5.5 v. dedicated standby mode active low for each channel. output power per channel: 2.8 w at 5 v into 4 with 10% thd+n or 0.7 w at 3.6 v into 8 with 1% thd+n max. selectable 3d sound effect. four gain setting steps: 3.5, 6, 9.5 and 12 db. low current consumption. psrr: 63 db typical at 217 hz. fast start-up phase: 7.8 ms. output short-circuit and thermal shutdown protection. flip-chip 18-bump lead-free package. refer to the datasheet for complete information on the ts4999. www.st.com
description of the demonstration board AN2933 2/10 1 description of the demonstration board the ts4999 demonstration board is designed to evaluate the ts4999, a fully-differential class d stereo power amplifier. the ts4999 device, in a flip-chip package, is mounted on a four-layer pcb. easily-accessible connectors on the board allow changing or driving the gain select pins (g0 and g1), the standby control pins for the left and right channels (stbl and stbr) and the 3d sound effect pin (3d). the differential gain of the ts4999 can be set to 3.5, 6, 9.5, or 12 db, depending on the logic level of the g0 pin (connected to pin 2 of s1) and g1 pin (connected to pin 2 of s2). note: an internal 300 k (+/-20%) resistor is placed between pins g0, g1 and gnd. when the pins are floating (s1 and s2 included), the gain is 3.5 db. in full standby (left and right channels off), these resistors are disconnected (hiz input). table 1. gain settings with g0 and g1 pins g1 g0 s1 s2 gain (db) gain (v/v) 00 3.51.5 01 62 10 9.53 11 124 ` 12 3 ` 12 3 ` 12 3 ` 12 3 ` 12 3 ` 12 3 ` 12 3 ` 12 3 table 2. truth table for 3d effect pin and standby pins 3d stbyl stbyr 3d effect left channel right channel 0 0 0 x stdby stdby 001offstdbyon 010offonstdby 011offonon 1 0 0 x stdby stdby 1 0 1 n/a n/a n/a 1 1 0 n/a n/a n/a 1 1 1 on on on
AN2933 description of the demonstration board 3/10 note: 1 an internal 300 k (+/-20%) resistor is placed between pins stbyl, stbyr, 3d and gnd. when the 3d pin is floating (s5 included), the 3d effect is switched off. when pins stbyl, stbyr are floating (s3 and s4 included), the amplifier is in full standby mode. in full standby (left and right channels off), the internal resistors of the gain and 3d effect pins (g0, g1 and 3d) are disconnected (hiz input). 2 when the 3d effect is switched on, both channels must be in operation or in shutdown mode at the same time. the amplifier?s inputs are capacitor-coupled , meaning that the -3 db cut-off frequency f c in hz is: with z in in , c in in farads, c1 = c2 and c3 = c4. 3 on the ts4999 demonstration board, c in = c1 = c2 = c3 = c4 = 220 nf. the input impedance zin changes with the set gain, as does f c . more information on component calculations is available in the ts4999 datasheet. f c 1 2 z in c in ?? ------------------------------------- =
description of the demonstration board AN2933 4/10 caution: when you apply the power supply through p1, do not invert the polarity since this will irreversibly damage the u1 amplifier. table 3. demonstration board connectors connector(s) description p1 power connector (v cc and gnd). power supply voltage from 2.5 to 5.5 v. s1, s2 gain setting connectors: s1 for the g0 , s2 for the g1 pin of the ts4999. the pins are connected as follows: ? 1 to v cc ? 2 of s1 to the g0 pin ? 2 of s2 to the g1 pin ? 3 to gnd jumper position: ? logical "1": pins 1 and 2 are shorted ? logical "0": pins 2 and 3 are shorted s3, s4 standby control connector: s3 for the left channel, s4 for the right channel. the pins are connected as follows: ? 1 to v cc ? 2 of s3 to the stbyl pin of the ts4999 ? 2 of s4 to the stbyr pin of the ts4999 ? 3 to gnd jumper position: ? pins 1 and 2 are shorted, the channel is operating. ? pins 2 and 3 are shorted or pin 2 is floating, the channel is in standby mode. s5 3d effect control connector. the pins are connected as follows: ? 1 to v cc ? 2 to 3d pin of the ts4999 ? 3 to gnd ? pins 1 and 2 are shorted, the 3d effect is on. ? pins 2 and 3 are shorted, the 3d effect is off. jp1 left channel input signal connector (gnd, l in +, l in - and gnd) jp2 right channel input signal connector (gnd, r in -, r in +and gnd) jp3 left channel output signal connector (gnd, l o +, l o - and gnd) jp4 right channel output signal connector (gnd, r o -, r o +and gnd) ` 12 3 ` 12 3 ` 12 3 ` 12 3 ` 12 3 ` 12 3
AN2933 description of the demonstration board 5/10 figure 1. schematic diagram gain select oscillator pwm pwm gain select standby control protection circuit bridge h bridge h lin+ lin- g0 g1 rin+ rin- stbyl stbyr lout+ d4 d6 a5 a7 e5 e7 c7 b4 e3 a3 d2 e1 c5 c3 b2 a1 lout- rout+ rout- rpvcc pgnd agnd avcc 3d effect c1 3d b6 lpvcc u1 ts4999 - fc18 c1 220nf c2 220nf c3 220nf c4 220nf 2 1 3 s2 g1 2 1 3 s1 g0 2 1 3 s3 stbl 2 1 3 s4 stbr vcc vcc vcc vcc linp linn g0 g1 rinp rinn stbl stbr 1 2 3 4 jp1 1 2 3 4 jp2 lin+ lin- gnd gnd rin+ rin- gnd gnd vcc 1 2 p1 vcc c6 1uf c7 1uf c5 100nf 2 1 3 s5 3d vcc vcc 1 2 3 4 jp4 header 4 1 2 3 4 jp3 header 4 table 4. component list for the demonstration board designation quantity description c1, c2, c3, c4 4 220 nf/16 v, smd ceramic capacitor, 0603 c5 1 100 nf/16 v, smd ceramic capacitor, 0603 c6, c7 1 1 f/16 v, smd ceramic capacitor, 0603 p1 1 2-pin header 2.54 mm pitch s1, s2, s3, s4, s5 5 3-pin header 2.54 mm pitch jp1, jp2, jp3, jp4 4 4-pin header 2.54 mm pitch u1 1 ts4999 class-d audio amplifier
demonstration board layout AN2933 6/10 2 demonstration board layout the following figures depict the top view and layers of the demonstration board. figure 2. pcb top layer figure 3. pcb middle layer 1 figure 4. pcb middle layer 2 figure 5. pcb bottom layer
AN2933 demonstration board layout 7/10 figure 6. top view and dimensions of the demonstration board
conclusion AN2933 8/10 3 conclusion to order the board online, go to http://www.st.com/stonline/domains/buy/buy_dev.htm , and use the order code steval-cca016v1.
AN2933 revision history 9/10 4 revision history table 5. document revision history date revision changes 27-mar-2009 1 initial release.
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